Tetracyclines cross-sensitivity

Bargman H. Lack of cross-sensitivity between tetracychne, doxycychne, and minocycline with regard to fixed drug sensitivity to tetracycline. J Am Acad Dermatol 1984 11(5 Pt l) 900-2. 

Bojs G, Moller H. Eczematous contact allergy to oxytetra-cycline with cross-sensitivity to other tetracyclines. Berufsdermatosen 1974 22(5) 202-8. 

Various skin reactions rarely may follow the use of any of the tetracyclines. More severe allergic responses are angioedema and anaphylaxis anaphylactoid reactions can occur even with oral administration. Other hypersensitivity reactions are burning of the eyes, cheilosis, glossitis, pruritus ani or vulvae, and vaginitis, which can persist for months after cessation of therapy. Fever, eosinophilia, and asthma also have been observed. Cross-sensitization among the various tetracyclines is common. 

Contact allergy to tetracyclines appears to be rare. Aureomycin ointment (Lederle) produced a dermatitis in a woman who applied the ointment to an area treated by dermabrasion. The patient was positive to chlortetracycline and di-methylchlortetracycline, but negative to oxytetracycline, tetracycline, and cymety-cline (Calnan 1967). Bojs and Moller (1974) reported three patients with contact allergy to oxytetracycline. Cross-sensitivity to tetracyclin and methacycline was demonstrated in two of the cases. 

Blank H, Cullen SI, Cataland PM (1968) Photosensitivity studies with demethyl-chlortetra-cycline and doxycycline. Arch Dermatol 97 1-2 Bojs G, Moller H (1974) Eczematous contact allergy to oxytetracycline with cross-sensitivity to other tetracyclines. Berufsdermatosen 22 202-208 Boman G, Nilsson BS, Saerens EJ (1973) Protein binding of rifampicin. Scand J Respir Dis [Suppl] 84 40-44... 

A rare side effect of tetracycline is photoonycholysis. This reaction was observed in a woman treated for 40 days with doxycycline (200 mg/daUy) (59 ). Contact dermatitis is also a rare complication of tetracycline therapy. Three cases of eczematous contact allergy to oxytetracycline have been reported. Cross-sensitivity to tetracycline and metha-cycline could be demonstrated by patchtesting in these cases (60 ). 

In a cell-free system inhibition can be shown to occur on both 70S and 80S ribosomes. However, in a more realistic in vitro setting intact prokaryotic (i.e., bacterial) cells are much more sensitive. The reason for this selectivity is that tetracyclines are actively transported into bacterial but not mammalian cells. In Gm- bacteria, at least, the more water-soluble compounds seem to cross through membrane channels (pores). The more lipid-soluble drugs (particularly MNC, Table 6-9) diffuse more readily through the lipoidal phases of the membranes. This energy-coupled process then leads to intracellular antibiotic accumulations. 

---